KR102414089B1 - Diiodosilane producing method - Google Patents

Abstract

[Project] An object of the present invention is to safely and efficiently produce diiodosilane on an industrial scale by reaction of phenylsilane and iodine.
[Solutions] To provide a method for producing diiodosilane, comprising at least a step of starting the reaction of phenylsilane with iodine at a low temperature, and after the dropping and mixing steps are completed, the reaction solution is transferred while continuously increasing the temperature little by little do.

Description

Method for producing diiodosilane {DIIODOSILANE PRODUCING METHOD}

The present invention relates to an industrial method for producing iodosilane, particularly iodosilane used as a film forming material for electronic material applications.

Halosilanes including iodosilane are widely used as raw materials for forming a silicon-containing film such as silicon nitride by a CVD method (chemical vapor deposition method) or ALD method (atomic layer deposition method) during semiconductor manufacturing.

In particular, diiodosilane attracts attention from the viewpoint of high reactivity and vapor pressure, and the demand is increasing in recent years.

The synthesis method of diiodosilane has been known for a long time, and it has been reported that it is produced in two steps by the reaction of phenylsilane and iodine.

Since the reaction of phenylsilane and iodine is a solid-liquid reaction, it is difficult to initiate the reaction, and furthermore, since it is an exothermic reaction, the conditions under which the stable reaction can be continued are difficult. In particular, at the end of the reaction, since the solid of iodine becomes small, the specific surface area increases, and it becomes highly active, it is very difficult to stably control the reaction.

Keinans performed this reaction without a solvent, but the scale is a small scale inside an NMR tube (about 4 mm inner diameter), and it is carried out by a low-temperature reaction of -20°C (refer to Non-Patent Document 1 below). Kerrigan et al. propose a manufacturing method on a 3L scale, in which the reaction is controlled to -6°C to +6°C while cooling in a low-temperature bath of -65°C, and then carefully returned to room temperature for 15 hours ( The following patent document 1). This indicates that unreacted raw materials still remain even at the end of the reaction. Although the manufacturing method of Kerrigans is scaled up compared to Keinans, there are still many challenges to be carried out on an industrial scale.

Specification of US Patent Application Publication No. 2016/0264426

J. Org. Chem. Vol. 52, 1987, pp. 4846-4851

In order to manufacture diiodosilane on an industrially suitable scale, even if it is the minimum, for example, 10L or more, preferably 30L or more, and in some cases, 100L or more, raw materials are injected in large quantities, such as production on a large scale. In addition, it is preferable that conditions such as being able to shorten the reaction time can be adopted. In that case, when a large amount of raw materials are injected and reacted, the reaction temperature is highly likely to be rapidly exothermic and runaway of the reaction, and it is necessary to review the method for controlling the reaction temperature for suppressing runaway of the reaction.

It is known to accelerate the progress of the reaction by carrying out the reaction at a certain high reaction temperature to shorten the reaction time. have.

The reaction for producing diiodosilane by the reaction of phenylsilane and iodine is a two-step reaction as shown in the following formula, but the first step, which is a solid-liquid reaction, is the rate-controlled, and the dephenyl reaction by hydrogen iodide in the second step is performed in the first step. progresses faster than Accordingly, it is considered that the accumulation of hydrogen iodide in the system is small. However, both the reaction of the 1st stage and the reaction of the 2nd stage are exothermic reactions, and when the reaction of the 1st stage proceeds, it becomes a situation that the combined exotherm of the 1st stage and the 2nd stage immediately occurs, and it is very important to deal with this.

Ph-SiH ₃ +I ₂ →Ph-SiH ₂ -I+HI

Ph-SiH ₂ -I+HI→I-SiH ₂ -I+H-Ph

In addition, in the said reaction formula, Ph represents a phenyl group.

The key to controlling an exothermic reaction is how much the reaction is maintained and how much heat is removed to prevent runaway of the reaction. Since it does not increase, the control of cooling method and temperature becomes very important.

As a result of earnest examination, the present inventors found that scale-up could be safely performed by continuously passing a reaction solution through a pipe whose temperature was controlled little by little, and led to the present invention.

That is, the present invention is a method for producing diiodosilane characterized in that phenylsilane and iodine are reacted in the presence of a solvent.

Also, particularly preferably, it is a method for producing diiodosilane by dropping phenylsilane and a catalyst to a mixture of a solvent and iodine in a reaction tank, and a reaction mixture comprising the solvent, iodine, phenylsilane, a catalyst and a reaction product in the reaction tank It is a method for producing diiodosilane, comprising the step of continuously or intermittently taking out a small amount from the reactor and transferring it while raising the temperature.

ADVANTAGE OF THE INVENTION According to this invention, manufacture on the industrial scale of diiodosilane by reaction of phenylsilane and iodine can be performed safely and efficiently.

In particular, in the method for producing diiodosilane by dropping phenylsilane and a catalyst to a mixture of solvent and iodine in a reaction tank, the reaction mixture containing the solvent, iodine, phenylsilane, catalyst and reaction product in the reaction tank is removed from the reaction tank. By including the step of taking out small portions continuously or intermittently and transferring the temperature while raising the temperature, the reaction rate is increased by increasing the temperature, and, in addition, small portions are taken out continuously or intermittently from the reaction tank and transferred while the temperature is raised. Even if the reaction rate is increased by this, control of the reaction temperature becomes easy, and the risk of runaway reaction can be reduced.

Further, preferably, by adopting an aspect in which the temperature of the step of continuously or intermittently taking out small portions from the reaction tank and transferring it while raising the temperature is +20 to +60°C, the reaction rate can be increased, and the control of the reaction temperature is It becomes easy, and the risk of a runaway reaction can be reduced less, and it is more preferable.

In addition, preferably, by adopting an embodiment in which a mixture of a solvent and iodine in the reaction tank is injected into the reaction tank at a low temperature of -20 ° C. to -100 ° C., when phenylsilane and a catalyst are added dropwise, the reaction temperature rises rapidly, and the reaction This runaway can be prevented, and it is more preferable.

Further, preferably, by employing an aspect in which the solvent is an aprotic solvent that does not react with diiodosilane and has a difference in boiling point from diiodosilane, the target diiodosilane can be easily obtained by distillation, It can extract|collect with a favorable yield, and it is more preferable.

Preferably, the solvent is chloroform, and after completion of the reaction, the solvent and benzene are removed by distillation, and when the diiodosilane is purified, the target diiodosilane can be easily and , which can be collected in a good yield, which is more preferable.

1 is a schematic diagram of an example of a reaction apparatus for producing the diiodosilane of the present invention.
2 is a schematic diagram of another example of a reaction apparatus for producing the diiodosilane of the present invention.
3 is a schematic diagram of another example of a reaction apparatus for producing the diiodosilane of the present invention.

The industrial method for producing diiodosilane of the present invention is to react phenylsilane and iodine in the presence of a solvent. The size of the reaction tank used in this case is not particularly limited, but for industrial production, the internal volume of the reaction tank This 10L or more, preferably 30L or more, more preferably 40L or more, and the upper limit is not particularly regulated, but if it becomes too large, the temperature in the reaction tank does not runaway, for example, phenyl in a reaction tank to which iodine and a solvent are introduced. In the case of starting the reaction by dropping the silane and the catalyst, or maintaining the temperature in the reaction tank at a relatively low temperature when the reaction is continued thereafter, enormous energy is required, so 200 L or less, preferably 100 L or less do.

In the reaction, iodine and a solvent are injected into the reaction tank at the start of the reaction. The temperature of the reactor is adjusted by circulating the refrigerant of the chiller through the jacket of the reactor to maintain a low temperature of -100 to +10 °C, preferably -30 to 0 °C, more preferably -20 to -10 °C. . After that, in the reaction tank, usually phenylsilane and catalyst at room temperature are added dropwise to start the reaction. At this time, the temperature in the reaction tank rises, but when phenylsilane and the catalyst are added dropwise, the temperature in the reaction tank is -100°C to +30 It is preferable that it is controlled at °C.

After completion of the dropwise addition of the phenylsilane and the catalyst, the temperature in the reaction tank is preferably maintained at -100 to +10°C, preferably -30 to 0°C, more preferably -20 to -10°C. In this way, the reaction is started. In the present invention, the reaction mixture containing the solvent, iodine, phenylsilane, catalyst and reaction product in the reaction tank is continuously or intermittently taken out in small portions from the reaction tank and transferred while the temperature is raised. It is preferable to include If the reaction is not completed even after passing through such a temperature increase transfer step, the reaction mixture is returned to the same reaction tank or introduced into another reaction tank, and the reaction mixture is continuously or intermittently transferred from the reaction tank to the reaction tank in small portions. The process of taking out and transferring while raising the temperature is repeated until the reaction is complete. In this case, the temperature in the reaction tank is -100 to +10°C, preferably -30 to 0°C, more preferably -20 to -10°C. It is preferable to keep it as

Further, in continuing the description of the method for producing diiodosilane of the present invention, the present invention will be described while citing an example of the reaction apparatus used, but citing and explaining the reaction apparatus will enhance the understanding of the present invention. For ease of use, the present invention is not limited to the use of these illustrated devices.

A schematic diagram of an example of the reaction apparatus used in the present invention is shown in FIG. The same is true for other drawings).

In Fig. 1, reference numeral 1 denotes a reaction tank provided with a constant temperature jacket for cooling on the side and bottom surfaces, reference numeral 2 a motor driven stirrer, reference numeral 3 a chiller for controlling the temperature of the coolant in the constant temperature jacket, reference numeral 4 a condenser (a heat exchanger for cooling), 5 is a pressure relief valve, 6 is an exhaust pipe, 7 is a supply of an inert gas such as nitrogen gas or argon gas (can be a cylinder), 8 is a valve (for inert gas supply), 9 is a dropping funnel, 10 is a valve (transfer reaction mixture) for), 11 is a circulation pump, 12 is a pipe pipe (in this example, a static mixer is built in), and 13 is a desired temperature for accelerating the reaction of the reaction mixture kept at a low temperature in the reactor (for example, +20 to +30) ℃) a constant temperature bath to keep the temperature raised, 14 is a thermostat to lower the temperature to a desired temperature (eg, -50 ~ +10 ℃) to calm the reaction, 15 is a valve (containing unreacted substances) A valve for putting the reaction mixture into the reaction tank [a valve for returning the reaction tank 1 in the case of Fig. 1]), 16 is a raw material inlet (solvent and iodine are put in. Also, the cover can be closed), 17 is It is a valve for taking out the reaction mixture at the end of the reaction (however, the valve 10 or 15 may be a three-way valve, and the reaction mixture may be taken out at the end of the reaction). In the above, the constant temperature bath 14 is shown in the drawings, but it does not need to exist when the temperature of the reaction mixture heated in the constant temperature bath 13 is operated under a condition that does not increase much (FIG. 2 or FIG. 3). The constant temperature baths 14a, 14b, 14c are also the same).

In the case of using the reaction apparatus shown in FIG. 1, after opening the valve 8 from the inert gas supply 7 and the inert gas such as nitrogen gas or argon gas (preferably nitrogen gas) to the inside of the reaction apparatus, , the solvent and iodine are injected into the reactor 1 from the raw material inlet 16 . The temperature of the reactor is adjusted by circulating the refrigerant of the chiller through the jacket of the reactor to maintain a low temperature of -100 to +10 °C, preferably -30 to 0 °C, more preferably -20 to -10 °C. . Thereafter, phenylsilane and the catalyst are added dropwise from the dropping funnel 9 to start the reaction. At the start of the reaction, the temperature of the reaction tank tends to rise. As described above, when the phenylsilane and the catalyst are added dropwise, , it is preferable that the temperature in the reaction tank is controlled to -100°C to +30°C. After the addition of the phenylsilane and the catalyst is finished, the temperature in the reaction tank is -100 to +10 ° C, preferably -30 to 0 ° C, more preferably -20 to -10 ° C. The temperature is adjusted by circulation in the jacket of the reactor. At this time, the inside of the reaction tank is preferably stirred with the stirrer 2 at all times.

It is preferable to use the iodine used for reaction in a solid form, and to refine it in dry inert gas. It is preferable that solid granular iodine flows easily through the pipe 12 etc. that it is a spherical granular thing. The particle size is also not particularly limited, but if it is too large, the specific surface area becomes small and the reaction slows down. It is preferable that it is this 0.1-10 mm, More preferably, it is 0.1-5 mm, It is preferable to use the thing of 0.1-3 mm more preferably.

As the solvent, an aprotic solvent that does not azeotrope with diiodosilane is used, as long as it has a boiling point difference from the reaction product, and the boiling point difference is in the case of atmospheric pressure, for example, +1 to +100 °C, preferably +20 to +100 °C, more preferably +60 to +100 °C, and the boiling point of diiodosilane may be higher or lower than 140 °C. In addition, although it does not specifically limit as an aprotic solvent, It is a boiling point in case a boiling point range is normal pressure, It is more preferable that it is +50-+120 degreeC.

As specific examples of the solvent, other than hydrocarbon solvents, halogenated hydrocarbon solvents and the like are used, for example, chloroform (boiling point 61 ° C.), dichloromethane (boiling point 40 ° C.), heptafluorohexane (boiling point 71 ° C.), deca. Fluoropentane (boiling point 55°C) and the like are mentioned, and in particular, chloroform is preferable from the viewpoint of boiling point, flammability, solubility of iodine, not azeotroping with diiodosilane, and cost. In addition, an aprotic solvent is usually not very soluble in iodine, but in the case of a halogen-based solvent, some solubility can be seen. The use of granular iodine is to improve the stirrability.

Although the usage-amount of a solvent is not specifically limited, Preferably it is 50 to 500 weight% with respect to the weight of iodine, More preferably, it is 100 to 200 weight%.

The temperature of the reactor is adjusted by circulating the refrigerant of the chiller through the jacket of the reactor to maintain a low temperature of -100 to +10 °C, preferably -30 to 0 °C, more preferably -20 to -10 °C. .

Next, phenylsilane and the catalyst are dropped from the dropping funnel 9, stirred with the stirrer 2, and the reaction is started. As described above, when the phenylsilane and the catalyst are added dropwise, the temperature in the reaction tank rises. It is preferable to maintain the temperature in the reaction tank at -100 to +30 ° C, and in the step of aging the reaction after the dropping, the temperature in the reaction tank is adjusted to -100 to +10 ° C, preferably -30 to 0 ° C, while stirring; More preferably, it is preferable to maintain at -20 to -10 °C.

Although it does not specifically limit as a catalyst to be used, Ethyl acetate, palladium (II) acetate, a triphenylphosphine oxide, palladium chloride, etc. are mentioned, Ethyl acetate is preferable.

The use ratio of phenylsilane and iodine is 80-150% of moles of iodine with respect to the number of moles of phenylsilane normally, Preferably it is 90-120%, More preferably, it is the range of 100-110%.

Although the usage-amount of a catalyst also changes with the kind of catalyst, Preferably, it is about 5 to 10 weight% with respect to the weight of phenylsilane.

Although the stirring speed of the stirrer 2 is not specifically limited, Usually, it is about 100-500 rpm.

The step of continuously or intermittently taking out the reaction mixture from the reactor in small amounts and transferring it while raising the temperature is preferably a process performed in a pipe for transporting the reaction mixture installed in the reactor, and the reaction mixture is transported and heated Pipes that carry out the process

(a) a process performed in a pipe connecting between adjacent reaction tanks using two or more reaction tanks (one-way: e.g., refer to FIG. 3, however, FIG. 3 is an example when three reaction tanks are used);

(b) in the step (a), returning the reaction mixture from the final reaction tank to any one of the reaction tanks, and transferring the reaction mixture in each pipe until the reaction mixture is taken out from the final reaction tank and raising the temperature; Repeatedly performed process (repetitive operation: eg, refer to FIG. 2, however, FIG. 2 is an example when two reactors are used); or

(c) repeating the steps of taking out the reaction mixture from the reaction tank using one reaction tank, and transferring the reaction mixture in a pipe returning to the reaction tank and raising the temperature (circulation operation: see FIG. 1 )

Either one is preferred.

Moreover, in any process, you may carry out the process of conveying and raising the temperature of the reaction mixture further in the piping for taking out the reaction mixture from the last reaction tank.

Depending on the scale of the reaction, in the initial stage of the reaction, as an aging step, low-temperature stirring at a temperature of -20°C or less in the reaction tank may be continued for several hours.

Next, each process will be described in more detail with reference to the drawings.

1, the solvent and iodine are injected into the reaction tank from the raw material inlet 16, and are maintained at -100 to +10°C, preferably -30 to 0°C, more preferably -20 to -10°C. When the mixture solution of phenylsilane and catalyst is dropped from the dropping funnel 9, the reaction starts and the temperature rises. As described above, when the phenylsilane and the catalyst are added dropwise, the temperature rises. It is preferably maintained at 100 to +30°C, and after that, the reaction mixture maintained at a temperature within the above range is stirred and aged in the reaction tank No. 1. By opening the valve (10), the reaction mixture flows intermittently or continuously in small portions through the pipe-type pipe (12), thereby operating the circulation pump (11) and raising the temperature to the desired temperature in the constant temperature bath (13) to accelerate the reaction. . Usually, the internal temperature of the piping in this thermostat 13 is +20 degreeC - +60 degreeC, Preferably it is +20 degreeC - +50 degreeC, It is preferable to maintain at +20 degreeC - +30 degreeC more preferably. The pipe in which the temperature is controlled may be a pipe-shaped pipe having a diameter immersed in the constant temperature tank 13, or a heat exchanger may be used. In some cases, there may be an internal structure typified by a static mixer that eliminates a temperature gradient inside the pipe. A static mixer is a static mixer (line mixer) without a drive part, and has a function in which the fluid which entered the mixer is sequentially stirred and mixed by an element.

In addition, the term "reaction mixture" here means a substance in the reaction system from the raw material mixture (including the catalyst) until the reaction proceeds and the reaction is completed, and the content and composition change depending on the reaction situation. That is, at the start of the reaction, the mixture of the raw material and the solvent is the main component, a small amount of the reaction product is included, and as the reaction progresses and approaches the completion of the reaction, the ratio of the raw material as it is decreases, and the ratio of the solvent and the reaction product This increases, and finally, at the completion of the reaction, the majority of the substances in the reaction system are the reaction product and the solvent, although it varies depending on the yield. The term "reaction mixture" including each of these steps means a substance in the reaction system from the raw material mixture until the reaction proceeds and the reaction is completed.

The material of the pipe 12 is glass, PFA (tetrafluoroethylene/perfluoroalkoxyethylene copolymer resin), ceramic, SUS, titanium, hastelloy (Ni/Cr/Mo/Fe alloy) and the like reaction mixture. It is preferable that it is made of an inert material that does not occur, and the thickness of the pipe 12 is not particularly limited because it also depends on the size of the reaction tank, but is usually 2 mm to 30 mm in inner diameter, preferably 3 mm to 20 mm. , when it is too thin, productivity tends to fall, and when it is too thick, it becomes a tendency for temperature controllability to fall. In some cases, a plurality of tubules may be arranged in parallel, or a heat exchanger of a similar type may be used. Although the length of the pipe is not particularly limited, it may be 10 cm to 10 m, and may have an internal structure that improves stirring efficiency inside, for example, the static mixer described above.

The reaction mixture is then returned back to the reactor via valve 15 . As described above, the constant temperature baths 14, 14a, 14b, and 14c are shown in FIG. 1 or other drawings, but when the need for cooling is low, these constant temperature baths 14, 14a, 14b, 14c are unnecessary. do.

The step of passing the reaction mixture through the pipe 12 maintained at a constant temperature by the constant temperature bath 13 at +20° C. to +60° C. in small portions may be performed continuously or intermittently while checking the temperature rise state of the constant temperature bath 13. may be done

The step of passing the reaction mixture through a pipe maintained at a constant temperature of +20°C to +60°C in small portions may be performed while passing between two or more reaction tanks (eg, see FIG. 3 ), and in some cases, between two or more reaction tanks may be repeatedly passed through (eg, see FIG. 2 ). In addition, in one reaction tank, the reaction mixture may be recycled (see, for example, FIG. 1 ). The temperature range of the process of conveying the inside of piping while heating up continuously is +20 - +60 degreeC, Preferably it is +20 degreeC - +50 degreeC, More preferably, it is +20 degreeC - +30 degreeC. In the stage where the reaction does not proceed sufficiently, before returning the reaction mixture to the reaction tank, the same temperature as the temperature in the reaction tank, that is, -100 to +10°C, preferably -30 to 0°C, more preferably -20 to- You may provide the process of cooling to 10 degreeC with the thermostat 14 etc.

Although the passage rate in the step of passing the reaction mixture through a pipe maintained at constant temperature in small portions is not particularly limited, it is usually 0.1 to 50 wt%/min, preferably 1 to 30 wt%/min relative to the total amount of the reaction mixture. min, more preferably about 5 to 20 wt%/min.

In addition, the flow rate is not particularly limited, but 100 ml to 50 L of the reaction mixture per minute (however, with respect to the total amount of the above reaction mixture, usually 0.1 to 50 weight % / min, preferably 1 to 30 weight % / min, more preferably can be made to flow in a range not inconsistent with about 5 to 20 wt%/min).

The completion of the reaction is the point at which solid iodine is removed from the reaction tank, and the valve 17 is opened to collect the reaction mixture. It will not specifically limit, if there exists a place where extraction|collection can be carried out, such as extraction|collection. Therefore, since it is visually confirmed whether solid iodine has disappeared from the reaction tank, it is preferable that at least a part of the reaction tank or piping is made of transparent glass or PFA. A reaction tank made of glass or a glass lining is preferable because it does not react with the raw material or product to be used either.

Since the obtained reaction mixture is purified by separating diiodosilane from a solvent and benzene as a by-product, it is usually separated by distillation. In order to obtain a higher purity diiodosilane, two-stage distillation is preferred.

Distillation may be performed by transferring the contents from the reaction tank to a distillation kiln, or short distillation may be performed directly from the reaction tank. When transferring the contents from the reactor to the distillation kiln, it may be taken out from the valve 17 at the lower part of the reactor, or the valve 10 or the valve 15 may be used as a three-way valve and taken out from there.

Next, an example of a reaction apparatus according to another embodiment that can be used in the present invention shown in FIG. 2 will be described.

In the reaction apparatus shown in FIG. 2, a route (10a valve, 11a) in which the step of passing the reaction mixture through a pipe in small portions is performed while passing between two or more reaction tanks (the first reaction tank 1a, the second reaction tank 1b) Circulation pump, 12a piped tubing, 13a thermostat to keep the temperature elevated, 14a thermostat to keep the temperature down to the desired temperature to calm the reaction (usually not needed if lowering the temperature is not necessary), 15a is a valve (a valve for introducing the reaction mixture containing unreacted into the second reaction tank 1b), and a route 10b valve for returning the reaction mixture from the second reaction tank 1b to the first reaction tank 1a; 11b circulation pump, 12b pipe-type piping, 13b thermostat to keep the temperature elevated, 14b thermostat to keep the temperature down to the desired temperature to quench the reaction (usually not required if lowering the temperature is not necessary); 15b has two piping routes of a valve (a valve for returning the reaction mixture containing unreacted substances to the first reaction tank 1a) In the drawings, the same reference numerals are attached to the same members as in FIG. In addition, the same numerals except for the alphabetic symbols are members having substantially the same functions as the members to which the same numerals are shown in Fig. 1, except for the points described above, and in this case as well, the temperature in the piping and the temperature conditions of the reaction tank Various conditions, such as, are the same as those of the above-described embodiment described with reference to Fig. 1. As in the case of Fig. 1, in a stage where the reaction does not proceed sufficiently, the above-mentioned description is given before returning the reaction mixture to the reaction tank. Even if the process of cooling to the same temperature as the temperature in one reaction tank, that is, -100 to +10 °C, preferably -30 to 0 °C, more preferably -20 to -10 °C, is installed by the thermostats 14a and 14b, etc. do.

In addition, although the dropping funnel 9 and the raw material inlet 16 do not exist in the 2nd reaction tank, the dripping funnel and the raw material inlet 16 may be present.

In addition, you may increase the number of reaction tanks as needed rather than what is shown in figure. In addition, in a reaction tank other than the 1st reaction tank among a plurality of reaction tanks, a dropping funnel or a raw material input port may not normally be required.

Next, a reaction apparatus according to another embodiment shown in FIG. 3 will be described.

The reaction apparatus shown in FIG. 3 is an example of a case in which the step of passing the reaction mixture through a pipe in small portions is performed while passing between two or more reaction tanks. are doing

In FIG. 3 , the reaction mixture that has passed through the pipe 12a of the first reaction tank 1a is not returned to the first reaction tank 1a, but is introduced into the other second reaction tank 1b through a valve 15a. do. In this case, various conditions such as the temperature in the pipes 12a and 13a and the temperature conditions in the reaction tanks 1a and 1b are the same as those of the embodiment described above with reference to FIG. The reaction mixture that has passed through the pipes 12b and 13b of the second reaction tank 1b is introduced into the other third reaction tank 1c through a valve 15b. In this case as well, various conditions, such as the temperature in the piping and the temperature condition of the reaction tank, are the same as those of the embodiment described above with reference to FIG. 1 , and thus description is omitted. Then, the reaction mixture in which the reaction is finally completed is taken out from the valve 17 of the third reaction tank 1c or, in some cases, is collected by passing through the pipes 12c and 13c of the third reaction tank 1c. As in the case of FIGS. 1 and 2 , in the stage where the reaction does not proceed sufficiently, the temperature is the same as the temperature in the above-described reaction tank before returning the reaction mixture to the reaction tank, that is, -100 to +10° C., preferably -30 to 0 °C, more preferably, the step of cooling to -20 to -10 °C may be provided by the thermostats 14a and 14b or the like. 14a, 14b, and 14c are thermostats for lowering and maintaining the temperature to the desired temperature described above when it is necessary to calm the reaction, but is usually unnecessary when the temperature does not need to be lowered.

In this figure, the reaction is completed by passing three reaction tanks, but when the reaction is not completed, it is good also as a design in which a reaction tank and piping are additionally extended. Alternatively, the reaction mixture may be returned from the third reaction tank to the second reaction tank, or the reaction mixture may be circulated between the second and third reaction tanks. In the case of serial production, this type of Fig. 3 is suitable, but at a cost.

Also in the reaction apparatus shown in FIG. 3, the same reference numerals are given to the same members as those in FIG. 1 in the drawing, and explanations are omitted. In addition, the same numerals except for the alphabetic symbols are members having substantially the same functions as the members to which the same numerals are shown in Fig. 1, except for the points described above, and in this case as well, the temperature in the piping, the temperature conditions of the reaction tank, etc. Various conditions of are the same as those of the above-described embodiment described above with reference to FIG. 1 , and thus description thereof is omitted.

In addition, although the dropping funnel 9 and the raw material inlet 16 do not exist in the reaction tank other than the 1st reaction tank among a plurality of reaction tanks, a dropping funnel and a raw material inlet may be present.

[Example]

The present invention is further illustrated by the following examples, but the present invention is not limited thereto.

(Example 1)

(Synthesis by chloroform solvent in 10L reactor)

3000 ml of chloroform solvent and 3012.5 g (11.87 mol) of iodine as synthetic solvents were injected into a 10000 ml flask set with a thermometer, condenser (cooled at -40 ° C), dropping funnel, and motor stirrer, and the inside of the reactor was cooled with the refrigerant from the chiller - It cooled to 30 degreeC, and the liquid mixture of 1214.0 g (11.22 mol) of phenylsilane and 40 ml of ethyl acetate was dripped over 140 minutes, stirring with a stirrer. The temperature of the liquid gradually rose to about -10°C during dripping, but a rapid temperature rise was not recognized. After completion of the dropwise addition, the reaction mixture was passed through a static mixer installed in a pipe passing through a constant temperature bath maintained at +30 ° C with a pump at a speed of 300 ml/min, and then passed through a pipe passing through a constant temperature bath at -30 ° C. After passing, the operation of returning to the reaction tank was continued for 6 hours. After confirming the disappearance of the iodine, cooling of the reaction tank was stopped, and the reaction mixture was passed through a constant temperature tank 13 maintained at +20°C again to confirm that the temperature of the reaction mixture did not rise above room temperature, and the reaction was stopped. In addition, in this device, there is no thermostat for calming the reaction indicated by reference numeral 14 in Fig. 1 . Two steps of vacuum distillation (concentration temperature: 45°C (51.3 kPa), distillation temperature: 60°C (6.9 kPa)) of the collected liquid was performed to obtain 2277.3 g (yield = 72%) of diiodosilane.

(Example 2)

(Synthesis by chloroform solvent in 50L reactor)

A thermometer, a condenser (cooled at -40 ° C), a dropping funnel, and a motor stirrer were set, and 15 L of chloroform solvent and 15.08 kg (59.42 mol) of iodine were injected as synthesis solvents into the 50 L reactor described in FIG. 1 filled with nitrogen gas, The inside of the reaction tank was cooled to -30°C with a refrigerant from a chiller, and a mixture of 6.07 kg (56.09 mol) of phenylsilane and 200 ml of ethyl acetate was added dropwise over 300 minutes while stirring. Although the temperature of the liquid gradually rose to about 0 degreeC during dripping, a rapid temperature rise was not recognized. After completion of the dropwise addition, the reaction mixture is passed through a static mixer installed in a pipe passing through a thermostat 13 maintained at 30° C. with a pump at a rate of 1 L/min, and then in a thermostat 14 at -30° C. After passing through the pipe passing through, the operation of returning to the reaction tank was continued for 12 hours. After confirming the disappearance of iodine, the cooling of the reaction tank is stopped, and after passing through the pipe passing through the thermostat 13 maintained at 20°C and the thermostat 14 maintained at 20°C, the reaction mixture It was confirmed that the temperature did not rise above room temperature, and the reaction was stopped. The collected liquid was subjected to vacuum distillation (same conditions as in Example 1) to obtain 11.62 kg (yield = 73%) of diiodosilane.

(Comparative Example 1)

(NEAT solvent-free synthesis)

118.2 g (0.47 mol) of iodine was injected into a 500 ml flask set with a thermometer, condenser (cooled at -40 ° C. Ar gas balloon installed on top of the condenser), dropping funnel, and motor stirrer, and cooled to -78 ° C (dry ice/ methanol bath) and 46.5 g (0.43 mol) of phenylsilane were added dropwise while stirring. After confirming that the phenylsilane had frozen, 1.2 ml of ethyl acetate was added dropwise, and stirring was continued to room temperature. During stirring, a rapid temperature rise was observed at around -20°C and increased to near 40°C, but the temperature gradually decreased (up to -5°C). At this time, the balloon slowly inflated. Stirring was continued until room temperature, and after reaching room temperature, stirring was continued for an additional 24 hours, and stirring was stopped. The collected liquid was subjected to vacuum distillation (distillation temperature: 60°C (6.9 kPa)) to obtain 59.5 g (yield = 49%) of diiodosilane.

As is clear from this result, only a small amount can be produced, the yield is also poor, the time required for the manufacturing process is long, and it is not suitable for industrial production.

(Comparative Example 2)

(Synthesis 500ml reactor using chloroform solvent)

100ml of chloroform and 103.7g (0.41mol) of iodine as synthetic solvents were injected into a 500ml flask set with a thermometer, condenser (cooled at -40℃, Ar gas balloon installed on top of the condenser), a dropping funnel, and a motor stirrer, -76 A mixture of 44.4 g (0.41 mol) of phenylsilane and 3.0 ml of ethyl acetate was added dropwise over 20 minutes while cooling to °C (dry ice/methanol bath) and stirring. A rapid temperature rise was not recognized during stirring, and stirring was continued to room temperature. After reaching room temperature, stirring was continued for an additional 24 hours, and stirring was stopped. The collected liquid was subjected to reduced pressure distillation (same conditions as in Example 1) to obtain 70.0 g (yield = 60%) of diiodosilane.

As is clear from this result, although the scale was increased compared to Comparative Example 1 using a solvent, only a relatively small amount could be produced compared to the one that took a long time, the yield was also poor, and it was not suitable for production on an industrial scale.

(Comparative Example 3)

(3000 ml reaction tank for synthesis using chloroform solvent)

Nitrogen gas was filled in a 3000 ml flask set with a thermometer, a condenser (cooled at -40 ° C), a dropping funnel, and a motor stirrer, 1400 ml of chloroform solvent and 1518.4 g (5.98 mol) of iodine were injected as synthesis solvents, The inside of the reaction tank was cooled to -30°C with a refrigerant, and a mixture of 611.6 g (5.65 mol) of phenylsilane and 24.0 ml of ethyl acetate was added dropwise at -30°C over 130 minutes while stirring. The temperature of the liquid gradually rose to about -10°C during dripping, but a rapid temperature rise was not recognized. After completion of the dropping, the temperature was raised to 5°C at 1°C/min, maintained at that temperature for 10 minutes, and then stirring was continued until it reached room temperature. After reaching room temperature, stirring was continued for an additional 24 hours, and stirring was stopped. The collected liquid was subjected to vacuum distillation (same conditions as in Example 1) to obtain 1220.1 g (yield = 76%) of diiodosilane.

As is clear from this result, although the scale was further increased than in Comparative Example 2 by using a solvent, a product in an amount suitable for industrial production was not obtained compared to the one that took an extremely long time, so it is suitable for production on an industrial scale Did not do it.

(Comparative Example 4)

(Synthesis with chloroform solvent 3000 ml dripping temperature = -20°C)

The same synthesis as in Comparative Example 3 was performed except that the temperature in the reaction tank (flask) was changed to -20°C at the time of dripping the mixed solution of phenylsilane and ethyl acetate. During dripping, the temperature of the liquid gradually rose to about 0°C, but a rapid temperature rise was not recognized. After distillation under reduced pressure (same conditions as in Example 1), 1211.3 g (yield = 75%) of diiodosilane was obtained.

As is clear from this result, when the dropping temperature of phenylsilane and ethyl acetate was set to a temperature higher than that of Comparative Example 3, the amount of diiodosilane obtained was not much different from that of Comparative Example 3, It took a long time and was not suitable for production on an industrial scale.

(Comparative Example 5)

(Synthesis with chloroform solvent 3000 ml dropping temperature = -10°C)

The same synthesis as in Comparative Example 3 was performed except that the temperature in the reaction tank (flask) was changed to -10°C at the time of dripping the mixed solution of phenylsilane and ethyl acetate. During dripping, the temperature of the liquid gradually rose to about 0°C, but a rapid temperature rise was not recognized. After distillation under reduced pressure (same conditions as in Example 1), 1219.1 g (yield = 76%) of diiodosilane was obtained.

As is clear from this result, when the dropping temperature of phenylsilane and ethyl acetate was set to a temperature higher than that of Comparative Example 4, the amount of diiodosilane obtained was not much different from that of Comparative Example 3 or Comparative Example 4, It is not possible to obtain a product in an amount suitable for industrial production, and the time required for the manufacturing process is long, which is not suitable for production on an industrial scale. It was found that an increase in the dropping temperature of phenylsilane and ethyl acetate did not contribute much to the improvement in production.

(Comparative Example 6)

(Shortening of synthetic phenylsilane dripping time using chloroform solvent)

The same synthesis as in Comparative Example 3 was performed except that the dripping time of the mixed solution of phenylsilane and ethyl acetate was changed to 60 min. During dripping, the temperature of the liquid rose gradually to about 10 degreeC. Although a rapid temperature rise was not observed, since the tendency to rise further was seen, dripping was stopped, and after confirming that the temperature of a liquid fell, dripping was continued further. After distillation under reduced pressure (same conditions as in Example 1), 1250.1 g (yield = 78%) of diiodosilane was obtained.

As is clear from this result, when the dropping time of phenylsilane and ethyl acetate is shortened compared to Comparative Example 3, the risk of increasing the temperature in the reaction system is sensed, and compared to the fact that production takes quite a long time, the diiodosilane obtained is The amount was not very different from the case of Comparative Example 3, and a product in an amount suitable for industrial production could not be obtained, so it was not suitable for production on an industrial scale. It was found that an increase in the dropping rate (reduction of the dropping time) of phenylsilane and ethyl acetate did not contribute to the improvement in production.

(Comparative Example 7)

(Increase of synthetic phenylsilane dropping time by chloroform solvent)

The same synthesis as in Comparative Example 3 was performed except that the dripping time of the mixed solution of phenylsilane and ethyl acetate was changed to 240 min. During the dropping, the liquid temperature was almost constant, and no rapid temperature rise was observed. After distillation under reduced pressure (same conditions as in Example 1), 1220.1 g (yield = 76%) of diiodosilane was obtained.

As is clear from this result, even if the dropping time of phenylsilane and ethyl acetate is longer than that of Comparative Example 3, the risk of increasing the temperature in the reaction system is alleviated, but compared to the fact that production takes quite a long time, the diiodosilane obtained The amount was not very different from the case of Comparative Example 3, and a product in an amount suitable for industrial production could not be obtained, so it was not suitable for production on an industrial scale. It turned out that the fall (increase of the dripping time) of the dropping rate of phenylsilane and ethyl acetate does not contribute to the improvement of the production volume.

(Comparative Example 8)

(Increase of stirring time at room temperature for synthesis with chloroform solvent)

After the mixture of phenylsilane and ethyl acetate was dripped, 1253.6 g (yield = 78%) of diiodosilane was obtained in the same manner as in Comparative Example 3 except that the stirring time after reaching room temperature was changed to 48 hours. lost.

As is clear from this result, even if the stirring time is doubled longer than that of Comparative Example 3, the amount of diiodosilane obtained is not much different from that of Comparative Example 3, compared to that the production time is extremely long, The amount of product suitable for industrial production was not obtained, so it was not suitable for production on an industrial scale. It turned out that even if it lengthens the stirring time after the inside of a reaction system becomes room temperature, it does not contribute to the improvement of production volume.

(Comparative Example 9)

(10000ml reaction tank for synthesis using chloroform solvent)

A thermometer, a condenser (cooled at -40 ° C), a dropping funnel, and a motor stirrer were set, and 3000 ml of a chloroform solvent and 3012.5 g (11.87 mol) of iodine were injected as a synthesis solvent into a 10000 ml flask filled with nitrogen gas, and from the chiller The inside of the reaction tank was cooled to -30°C with a refrigerant, and a mixture of 1214.0 g (11.22 mol) of phenylsilane and 40 ml of ethyl acetate was added dropwise over 140 minutes while stirring. During the dripping, the temperature of the liquid gradually rose to about -10°C, but a rapid temperature rise was not recognized. After completion of the dropwise addition, the temperature was raised to 5°C at 1°C/min, maintained at that temperature for 10 minutes, and then stirring was continued until it reached room temperature. At this time, the temperature of the liquid increased from around 15°C to about 30°C at once. When the temperature of the chiller was lowered to 0°C, the liquid temperature was lowered. After continuing stirring at 0°C for 1 hour, the temperature was raised to 5°C at 1°C/min and stirred for 1 hour. At this time, the liquid temperature was 10°C, and a clear difference was observed from the chiller temperature (5°C). Thereafter, the temperature was raised to 20°C at 1°C/min and stirring was continued for an additional 24 hours, and stirring was stopped. The collected liquid was subjected to vacuum distillation (same conditions as in Example 1) to obtain 1834.5 g (yield = 58%) of diiodosilane.

Although prepared on the same scale as Example 1, Comparative Example 9 does not have a step of continuously or intermittently taking out the reaction mixture in small portions from the reactor and transferring it while raising the temperature, so compared with Example 1, the process time is also It was long, the quantity was small, and the yield was also bad, so it was not suitable for industrial production.

(Comparative Example 10)

(Synthesis using chloroform solvent 10000ml reaction tank temperature control and stirring to room temperature)

The same process as in Comparative Example 9 was followed, and the dripping of the mixed solution of phenylsilane and ethyl acetate was terminated. In the step of raising the temperature to room temperature after the phenylsilane dropwise addition and stirring, the temperature was raised to 5°C at 1°C/min, held at that temperature for 10 minutes, and then heated to 0°C and maintained for 5 hours. Then, it heated up to 5 degreeC at 1 degreeC/min, and after holding for 2 hours, the temperature was raised to 10 degreeC at 1 degreeC/min, and it hold|maintained for 1 hour. From there, the temperature was raised to 20°C at 1°C/min and stirring was continued for 24 hours after reaching 20°C. At this time, the temperature of the liquid did not exceed the chiller temperature and the temperature did not rise. Except for that, the same steps as in Comparative Example 9 were followed to obtain 1819.4 g (yield = 57%) of diiodosilane.

Compared with Comparative Example 9, it was possible to return to room temperature in a more stepwise manner, but the process time was long, and although the same apparatus as in Example 1 was used, the quantity was less and the yield was poor compared to Example 1, and industrial production was not suitable for

[Table 1]

Note) In the table, "theoretical batch quantity" refers to the quantity when it is assumed that all of the input materials reacted 100%, and in reality, all 100% did not react, so it is necessary to consider the yield.

"Drop" in the remarks column in a table|surface means dripping of the liquid mixture of phenylsilane and ethyl acetate.

[Industrial Applicability]

In the method for producing diiodosilane of the present invention, diiodo as a raw material for forming a silicon-containing film such as silicon nitride by a CVD method (chemical vapor deposition method) or ALD method (atomic layer deposition method) during semiconductor manufacturing It can also contribute to shortening of the manufacturing process time of dosilane, and can be usefully applied to industrial manufacture.

1 reactor
1a first reactor
1b second reactor
1c third reactor
2 stirrer
3 chiller
4 Condenser (heat exchanger for cooling)
5 pressure relief valve
6 exhaust pipe
7 Inert gas supply
8 valve
9 drip funnel
10, 10a, 10b, 10c valves
11, 11a, 11b, 11c circulation pump
12, 12a, 12b, 12c piping
13, 13a, 13b, 13c thermostat
14, 14a, 14b, 14c bath
15, 15a, 15b, 15c valves
16 Raw material inlet
17 valve

Claims (4)

A method for producing diiodosilane by dropping phenylsilane and a catalyst to a mixture of a solvent and iodine in a reaction tank, wherein the reaction mixture including the solvent, iodine, phenylsilane, catalyst and reaction product in the reaction tank is added little by little from the reaction tank A method for producing diiodosilane comprising the step of continuously or intermittently taking out and transferring while raising the temperature,
The solvent is an aprotic solvent that does not azeotrope with diiodosilane, and has a boiling point difference from the reaction product,
The catalyst is selected from the group consisting of ethyl acetate, palladium (II) acetate, triphenylphosphine oxide, and palladium chloride,
The temperature of the process of taking out small amounts continuously or intermittently from the reactor and transferring it while raising the temperature is +20 to +60 ° C,
The "in small amounts" means a rate of 0.1 to 50% by weight/min with respect to the total amount of the reaction mixture, the method for producing diiodosilane. The method according to claim 1,
The step of continuously or intermittently taking out the reaction mixture in small portions from the reactor and transferring it while raising the temperature is a process performed in a pipe for transporting the reaction mixture installed in the reaction tank, and the process of transporting and raising the temperature of the reaction mixture is as follows (a), (b), a process selected from any one of (c), a method for producing diiodosilane.
(a) a process performed in a pipe connecting between adjacent reaction tanks using two or more reaction tanks; or
(b) in the step (a), returning the reaction mixture from the final reaction tank to any one of the reaction tanks, and transferring the reaction mixture in each pipe until the reaction mixture is taken out from the final reaction tank and raising the temperature; a process to be repeated, or
(c) repeating the steps of taking out the reaction mixture from the reaction tank using a single reaction tank, and transferring the reaction mixture in a pipe returning to the reaction tank and raising the temperature. delete delete

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